The present invention relates generally to a fitting for a containment chamber and, more particularly, to a matingly engaged flexible entry boot for providing a fluid-tight fitting between a wall of a fluid containment region and a conduit passing through the wall.
For many years in the area of fluid fittings, some structures have been of a permanent variety which include welding or bonding of the exterior wall of the conduit to the wall opening of the fluid containment region through which the conduit extends. Other structures, such as that disclosed in U.S. Pat. No. 4,775,073, disclose the use of a fitting system which is installed at a factory and then adapted by the user to fit his needs. Such manufacturing processes of fluid containment structures are limited since they require built-in fitting systems for which some users may not have any need, use and/or desire.
Moreover, many of these fitting structures require fixedly attaching the conduit at an angle perpendicular to the containment region wall. For example, U.S. Pat. Nos. 5,129,684; 4,775,073; 4,492,392; and 2,310,877 teach conduit fitting systems which require the conduit to be placed at an angle normal to the containment wall. If the angle is not normal, the fluid-tight seal will be breached. Such requirements greatly inhibit the use of the fitting system since a conduit cannot be inserted into the containment wall at angles which are other than normal while still maintaining a fluid-tight environment.
A prior art bulkhead fitting 100 is shown in FIG. 6. This fitting 100 includes a threadingly engageable flanged member 102 outside the containment region. Inside the containment region is a gasket 104; and the mating member 106 for threading engagement with the flanged member 102. The threads both on member 102 and mating member 106 are square threads. At an end distal from the threadingly engaged end, mating member 106 includes an annular lip 108, over which a flexible boot portion 110 is placed. A conduit (not shown) is inserted through opening 112, and worm gear hose clamps (not shown) secure the boot portion 110 and conduit at clamping areas 114 and 116, respectively. However, several drawbacks exist with this fitting 100. Due to the circumferential seal between annular lip 108 and boot portion 110, if the materials of which boot portion 110 and mating member 106 are made do not have exactly the same coefficient of expansion, lip 108 and boot portion 110 will expand and contract at different rates. This will make fitting 100 prone to leakage. In fact, under normal use pressures, such as water pressure and/or other exterior pressures, eg. backfill pressure, boot portion 110 may dislodge completely from mating member 106. Further, if to prevent such leakage, boot portion 110 is made to be tightly tensioned over lip 108 at any temperature and/or pressure, boot portion 110 will be very difficult to remove for repair and/or replacement; and it will be extremely difficult to replace while within the strict confines of a buried sump or the like. Further, lip 108 is quite thin, and substantially thinner than the remainder of mating member 106; as such, lip 108 may be weak and prone to breakage. A further disadvantage is that the same sized fitting 100 is used to accommodate various diameter piping systems. As the boot portion 110 is quite large, when a smaller diameter pipe (such as a 1" pipe) is installed therein, the consequently large gaps therearound are prone to fill with backfill gravel and the like, further making fitting 100 prone to failure.
Thus, it is an object of the present invention to provide a fluid-tight entry boot for use with fluid-tight fitting systems, which boot has the advantage of easy installation for a user. It is a further object of the present invention to provide such an entry boot which has at least one seal member substantially fully disposed within the containment region, which advantageously protects the seal member from ground and weather exposure. It is yet a further object of the present invention to provide a flexible entry boot which may be repaired and/or replaced without detaching the entire boot assembly from the wall of the containment region. Yet still further, it is an object of the present invention to provide such an entry boot which allows for the insertion of a conduit into a containment wall opening at angles which are not necessarily normal while maintaining a fluid-tight environment. Still further, it is an object of the present invention to provide such a fluid-tight system which is of simple construction and relatively easy and inexpensive to manufacture. It is yet a further object of the present invention to provide such an entry boot which can suitably withstand the effects of thermal expansion and contraction, while yet being quick and simple to replace and/or repair.